Hermetically sealed motor-compressor



. 28, 1967 KOITIRO MATUKI ETAL 3,306,524

HERMETICALLY SEALED MOTOR-COMPRESSOR Filed March 5, 1965 4 Sheets-Sheet 1 fiy/d 7/? K MA TUKI, K HIM/V0,

AND 7' Sou/41mm INVENTORS ATTORNEYS- Feb.28,1967

Filed March 5, 1965 KOITIRO MATUKI ETAL HERMETICAL Y SEALED MOTOR-COMPRESSOR 4 Sheets-Shed 2 F? 54 ggflog g; 3 g? :47 64 ZIA TUKI,

. ram/0, MID 46' 44 4'6 '7? SUNAHARA INVENTORS ATTORNEYS 1967 KOlTlRO MATUKl ETAL HERMETICALLY SEALED MOTOR-COMPRESSOR Filed March 5, 1965 4 Sheets-Sheet 4 K MAW/ 1, y HIRAMQ A110 7? SUAMf/AQA INVENTORS all/KM M MJMML L AT TO R N E Y 5 3 306,524 HERMETICALLY SEA LED MOTOR-COMPRESSOR Koitiro Matuki, Ohta, Gunma, and Yutaka Hirano and Toshio Sunahara, Oh-ra-gun, Gnnma, Japan (all Tokyo Sanyo Electric Co., Ltd., 180 Aza Oh-tana, haza Sakata, Oh-izumi-cho, Ola-ra-gun, Gunma, Japan) Filed Mar. 5, 1965, Ser. No. 437,490 Claims priority, application Japan, Mar. 5, 1964, 39/17,349; Mar. 10, 1964, 39/155,702; Mar. 13, 1964, 39/19,584; May 15, 1964, 39/37,862; June 16, 1964, 39/ 17,959

Claims. (Cl. 230-58) This invention relates generally to motor-compressor units, and more specifically to an improved hermetic motor-compressor unit for use in a refrigeration system.

Hermetic motor-compressor units find important use in the refrigeration art, and it is of further importance in that are that these hermetic motor-compressor units have as narrow a width as possible to permit the design of refrigerator cabinets wherein only a small proportion of the available space need be alloted to the motor-compressor unit.

In the motor compressor unit in which the motor and compressor are arranged in vertical relation, the possible minimum diameter of the casing enclosing the motorcompressor unit depends on and is limited to the outside diameter of the motor in consideration of the horizontal vibration stroke of the unit. The possible minimum height of the casing depends on and is limited to the total height of the motor and compressor in consideration of the vertical vibration stroke of the unit.

The principal object of the invention is, therefore, to provide a hermetically sealed motor-compressor unit which is assembled within the above limitation, more compactly than is possible with the hermetic motor compressor units presently known in the art.

Another object of the invention is to provide a sealed motor-compressor unit of the type wherein a structure which carries the operating parts thereof is resiliently supported in an improved manner within a sealed casing so as to minimize noises and eliminate damage to the structure during shipping of the unit.

A further object of the invention is to a novel arrangement for lubricating the piston and cylinder of the compressor portion of the unit.

A still further object of the invention is to provide a novel means for producing a forced convection of the refrigerant gas within the sealed casing for cooling various parts of the unit.

Further objects and advantages reside in the cooperation of parts of the structure which facilitates the manufacture and assembly of the improved motor-compressor unit and by novel combinations and arrangements to provide an eflicient, quiet operating and durable unit, as will more fully appear in the course of the following descrip tion.

In the drawing:

FIGURE 1 is a transverse vertical sectional view of a hermetically sealed motor-compressor unit constructed in accordance with the invention;

FIGURE 2 is a side view, partly in section, of the motor-compressor unit taken along the line 22 of FIGURE 1;

FIGURE 3 is a horizontal section taken on the line 3-3 of FIGURE 1 in a direction upwardly from the bottom of the motor-compressor unit;

FIGURE 4 is a side view, partly in section, of the motor and compressor assembly substantially taken along the line 44;

FIGURE 5 is a front view, partly in section, of the motor rotor;

United States Patent 0 3,306,524 Patented Feb. 28, 1967 FIGURE 6 is a plan view of FIGURE 5;

FIGURE 7 is a plan view of the cylinder housing of the compressor with a pair of muffler chambers;

FIGURE 8 is a plan View of the main frame illustrated in FIGURE 1;

FIGURE 9 is a bottom view of the main frame;

FIGURE 10 is a plan view of the annular oil trough illustrated in FIGURE 1; and

FIGURE 11 is a sectional view taken along the line 1111 of FIGURE 10.

Referring to the drawings for a detailed description of the invention, the hermetically sealed motor-compressor unit is particularly adaptable for use with refrigeration apparatus wherein a refrigerant is compressed, condensed and evaporated in a repeated cycle.

A sealed casing 21 encloses a motor and a compressor, generally indicated at 22 and 23, respectively. The casing 21 comprises a lower cup-shaped member 24 and a top cover member 25 which are welded together at 26 to provide a hermetically sealed enclosure for the motor 22 and compressor 23.

A main frame member 27 on which the motor 22 and compressor 23 are entirely assembled in vertical relation at the upper and lower sides thereof, provides a vertically extending bearing 28 for a drive shaft 29 between the motor 22 and compressor 23.

The motor 22 may be a single-phase induction motor which includts a rotor 30 connected to a hub 31, which is in turn pressed on the drive shaft 29, so that rotational movement is imparted to the drive shaft 29. The frame member 27 is provided with four upwardly extending support legs 32 on which a stator 33 for the motor 22 is rigidly mounted by means of bolts 34 as more clearly shown in FIGURES 2 and 4. The stator 33 includes the field windings 35 which are connected to a cable 36. .The cable 36 is in turn connected without the lower casing member 24 by the terminal assembly 37 as shown in FIGURE 2.

The rotor 30 may be a squirrel-cage rotor which com prises an iron core accumulation 38 and two aluminium short-circuit rings 39 and 40 at the top and bottom thereof. These two aluminium short-circuit rings 39 and 40 are incorporated to each other and pressed to the iron core accumulation 38 by diecasting.

The drive shaft 29 has an enlarged integral portion 41 provided with an integral pin 42 which has its vertical axis offset horizontally relative to the vertical axis of the shaft 29 so as to be rotated around the vertical axis of the shaft 29'. The offset pin 42 is adapted to operate parts of the compressor 23. The compressor 23 includes a housing 43 having a horizontally disposed cylinder 44 formed therein. The housing 43 has a plane top surface that is secured in sealing engagement to the plane bottom surface 45 of the frame 27 by bolts 46 and 47 as more clearly shown in FIGURES 3 and 4. A piston 48 located within the cylinder 44 is welded or otherwise suitably secured to a horizontally disposed collar 49 provided with aligned elongated openings 50 for receiving the oifset pin 42. A horizontally disposed slider 51 fits within the collar 49 and is provided with a vertical opening which receives the offset pin 42 and with cylindrical outer wall surfaces forming a bearing for collar 49 (see FIG- URES l and 3).

A valve plate 52 and a cylinder head 53 are located at the outer end of the housing 43. The valve plate 52 and the cylinder head 53 are clamped in place upon the outer end of the housing 43 by bolts 54. The valve plate 52 is provided with a pair of openings, an inlet port 55 and an outlet port 56 (see FIGURE 1). The inlet port 55 and the outlet port 56 are provided with valves of any known type, respectively. The cylinder head 53 is hol lowed out as at 57 to communicate through the inlet port 55 with the cylinder 44. This provides an inlet passage for refrigerant to be compressed. The head 53 is also hollowed out as at 58 which communicates through the outlet port 56 with the cylinder 44 to provide a discharge passage for refrigerant compressed by the compressor piston 48.

According to the invention, the housing 43 is provided with a pair of rnufiler chamber 59 and 60 in horizontal relation at opposite sides of the cylinder 44 as more clearly shown in FIGURE 7. These muffler chamber 59 and 60 are cast as integral parts of the cylinder housing 43 and communicate through the respective passageways 61 and 62 with the hollowed portions 57 and 58. The mufiler chamber 59 serves as an intake mufiler and the muffler chamber 60 serves as an exhaust mufiler.

A hole 63 is provided in the bottom of the muffler chamber 59 (FIGURE 4). The hole 63 is sealed by a cap 64- to which one end of a pipe 65 is secured. The pipe 65 is bent upwardly and has its opposite end terminating in the vicinity of the top edge of the motor stator 33. The mufiier chamber 6t) is also provided with a hole 66 at its bottom. The hole 66 is sealed by a cap 67 to which one end of a pipe 68 (FIGURE 3) is secured. The pipe 68 extends from the cylinder housing 43 to another exhaust mufiier device generally indicated by the reference numeral 69 which is in turn connected through a connection pipe 70 to a compressed refrigerant supply pipe 71. The pipe 71 extends outside of the casing 21 and is connected to an evaporator of the refrigeration apparatus (not shown). In FIGURE 3, 72 is a connector for introducing the refrigerant into the casing 21 and 73 is a connector for evacuating the interior of the casing 21 when it is assembled.

The internal assembly comprising the frame 27, the motor 22 and the compressor 23 is supported by three resilient mounting or supporting devices generally indicated with the numeral 81 These three resilient supporting devices 80 are arranged on the under-side of the frame 27 and spaced from each other at regular angular intervals, preferably at 120 intervals on a circle having a diameter smaller than the outside diameter of the motor 22. Each of these resilient mounting devices 80 comprises a coil spring 81 and a pair of mounting elements 82 and 83 at the opposite ends of the coil spring 81. The mounting element 82 is generally cone-shaped and secured at its shank portion 84 to the main frame 27 as by threading. The other mounting element 83 is fixed on a raised bottom 85 of the lower casing member 24. The raised bottom 85 is substantially horizontal. The mounting element 83 has a spiral groove cut therein for threadably receiving the lower end portion of the coil spring 81. The upper end portion of the coiled spring 81 is positioned around the cone-shaped element 82 and is always in contact with the bottom surface of the frame 27. The element 82 may also have a spiral groove for receiving the upper end portion of the spring 81.

It would be understood that according to the invention since the three resilient mounting devices 86 are arranged on a circle which is smaller than the outer periphery of the motor 22, the diameter of the casing 21 can be reduced to the utmost extent. In addition as the mounting element 83 for receiving the lower end portion of the spring 81 is fixed on the raised bottom of the casing 21 the length of the spring 81 may be shortport of the internal assembly. The compressor housing 43 and the pair of mufiler chambers and 60 at its opposite sides are disposed on an are between two resilient mounting devices. In this manner it becomes possible ened and accordingly it is possible to ensure stable supto compactly accommodate the two muffler chambers 59 and 60 within the casing 21.

As already described before, the cylinder housing 43 45 of the frame 27 by bolts 46 and 47. The first two bolts 46 extend through bores 91 (FIGURE 7) in the peripheral wall of the housing 43 to threaded holes 91 (FIGURE 19) in the frame 27 within which the respective ends of the bolts 46 are fitted and secured. The threaded holes 91 may extend through the frame 27. The second two bolts 47 are disposed so as to extend through the pipe connector caps 64, 67, the holes 63, 66 and the mufiler chambers 59, 61). The threaded holes 92 in the frame 27 for receiving the respective ends of the bolts 37 terminate within two of the legs 32 for supporting the stator 33. The frame member 27 has radial extensions for mounting the four support legs 32 and three resilient supporting devices 80, as indicated with the numerals 93 and 94, respectively (see FIGURES 8 and 9). Two of the extensions 93 for mounting support legs 32 are integral with extensions 94 for mounting resilient supporting devices while the remaining extensions are independently formed.

The terminal assembly 37 extends through the casing member 22 and is disposed substantially on the opposite side from the exhaust mufller device 69 with respect to the cylinder housing 43 and with respect to the resilient mounting device 80 opposite to the cylinder housing 43. In this manner the whole unit may be assembled in a compact and balanced manner.

Lubricant is contained in the bottom of the casing 21. The numeral indicates an oil reservoir in the bottom of the casing member 24. A downwardly extending pipe 101 is secured to the eccentric pin 42 which is formed as an extension of the drive shaft 29. The end 102 of the pipe 101 projects into the oil reservoir 100 and is disposed on the axis of the drive shaft 29 so that rotation of the eccentric pin 42 around the axis of the shaft 29 causes rotation of the pipe 101 about its end N2. When the eccentric pin 42 with the pipe 101 is rotated, lubricant from the reservoir 160 is raised by the pipe 101 owing to the centrifugal force and is caused to flow through a hole 103 drilled through the eccentric pin 42 and terminating in communication with the lower portion of a spiral groove 104 out in the surface of the shaft 29 so as to lubricate it within the bearing 28. The pin 42 is provided with a horizontal hole 165 extending from the vertical hole 103 so as to provide lubrication to the pin 42, the slider 51 and collar 49.

In a preferred embodiment of the invention, an annular trough 111 is positioned between the bottom of the stator windings 3-5 and the top surface of the frame so as to receive the windings 35. The annular trough 111 is shaped in a V- or U-section and made of insulating and refrigerant resist material, for example, polyester, cotton or glass cloth impregnated or coated with resins such as acryl resin, polyurethane resin, epoxid resin and polyester resin. The annular trough 111 is provided with an elongated opening 112 which is disposed above a small oil reservoir cavity 113 formed on the top surface of the frame, at the back of which the cylinder housing 43 is mounted. The frame 27 is provided with a hole 114 extending therethrough to connect the oil reservoir cavity 113 with the bottom surface of the frame above the piston 48. In this manner, lubricant oil scattered from the drive shaft 2? due to the centrifugal force drips along the windings 35, is received by the annular trough 111, drops through the opening 112, is collected in the cavity 113 and then supplied through the hole 114 to the piston 48. Preferably, the annular trough 111 is provided with another small opening 115 on the opposite side from said elongated opening 112 so that the cable 36 connected to the windings 35 may extend through this opening.

A sleeve extends downwardly from the top cover casing 25 so as to surround the top end 121 of the drive shaft 29. This sleeve 12!) provides an air cushion bearing for the top end 121 of the shaft 29 during its rotation.

Preferably, each of the top and bottom short-circuit rings 39 and 40 of the motor rotor 30 is formed with a plurality of radially directed blades 122 and 123 so that a forced convection of the refrigerant gas may be produced to cool the operated parts. The reference numeral 124 indicates a plurality of ventilation openings which are formed in the frame member 27. In order to prevent contact of the blades 122 with the sleeve 120 during operation, it is desirable to plane off the inner edge 125 of each of the blades 122.

What we claim is:

1. A hermetically sealed motor-compressor comprising a compressor, said compressor including a cylinder and having an intake muffler chamber and exhaust muffler chamber horizontally disposed on opposite sides of the cylinder, a motor driving the compressor, a frame having the motor mounted on the upper side thereof and the compressor mounted on the lower side thereof, a hermetically sealed casing enclosing the motor, compressor and frame, said casing having raised seats in the bottom thereof, and three resilient support means resiliently supporting the frame at the underside thereof, said three resilient support means being arranged in angularly spaced relation at substantially 120 intervals on a circle having a diameter smaller than the outside diameter of the motor and being mounted between the bottom surface of said frame and the raised seats formed in the bottom of said casing, and said cylinder with said two mufiler chambers being disposed between two of said three resilient support means in such a manner that said two muffler chambers on the opposite sides of said cylinder are arranged substantially on the portion of said circle between said two resilient support means.

2. A hermetically sealed motor-compressor compris ing a compressor, said compressor including a cylinder and having an intake muffler chamber and exhaust muffler chamber horizontally disposed on opposite sides of the cylinder, a motor driving the compressor, said motor comprising a rotor and a stator, a frame having the motor mounted on the upper side thereof and the compressor mounted on the lower side thereof, a plurality of support legs extending upwardly from said frame and rigidly supporting said stator, a hermetically sealed casing enclosing the motor, compressor and frame, and three resilient support means resiliently supporting the frame at the underside thereof, and bolts securing the cylinder housing comprising said cylinder and said two muflier chambers to the bottom surface of said frame, said bolts extending through said muffler chambers and engaging in threaded holes which extend from the bottom surface of the frame part way into the frame toward said support legs.

3. A hermetically sealed motor-compressor as claimed in claim 2, in which said three resilient support means are arranged in angularly spaced relation on a circle having a diameter smaller than the outside diameter of the motor, and said cylinder with said two mufiler chambers being disposed between two of said three resilient support means.

4. A hermetically sealed motor-compressor as claimed in claim 2, in which said three resilient support means are arranged in angularly spaced relation at substantially 120 intervals on a circle having a diameter smaller than the outside diameter of the motor, the bottom of said casing having raised seats in the bottom thereof, said support means being mounted between the bottom surface of said frame and the raised bottom seats in said casing, and said cylinder with said two mufller chambers being disposed between two of said three resilient support means in such a manner that said two muffler chambers on the opposite sides of said cylinder are arranged substantially on the portion of said circle between said two resilient support means.

5. A hermetically sealed motor-compressor comprising a compressor including a housing having a horizontally disposed cylinder formed therein and a piston located within said cylinder, said housing being provided with an intake muffler chamber and exhaust mufller chamber horizontally disposed on opposite sides of said cylinder, a motor driving the compressor, said motor including a drive shaft having an offset pin thereon having its vertical axis offset horizontally relative the vertical axis of said drive shaft, said piston being connected to said offset pin so that said piston is reciprocated within said cylinder when said drive shaft is rotated, a frame having the motor mounted on the upper side thereof and the compressor on the lower side thereof, a hermetically sealed casing enclosing the motor, compressor, and frame, said casing having raised seats in the bottom thereof, three resilient support means resiliently supporting the frame at the underside thereof, said three resilient support means being arranged in angularly spaced relation at substantially intervals on a circle having a diameter smaller than the outside diameter of the motor, said support means being mounted between the bottom surface of said frame and the raised bottom seats in said casing, and said cylinder with said two muffler chambers being disposed between two of said three resilient support means in such a manner that said two muffler chambers on the opposite sides of said cylinder are arranged substantially on the portion of said circle between said two resilient support means, and a lubrication system, said lubrication system comprising an oil reservoir formed in the bottom of said casing, means for raising lubricant from said oil reservoir towards said drive shaft of the motor through the utilization of the centrifugal force during operation of said motor, an annular trough which is positioned between the bottom of the stator windings and the top surface of the said frame so as to receive said windings, said annular trough having an open channel section and being made of insulating and refrigerant resistant material and being provided with an opening therein, said frame having a hole therethrough for receiving lubricating fluid from said opening, said opening and said hole together forming a passageway for introducing lubricant toward the piston of the compressor.

References Cited by the Examiner UNITED STATES PATENTS 2,801,045 7/1957 Philipp 230235 3,075,686 1/1963 Steinhagen 230235 X 3,187,994 6/1965 Valbjorn 23058 X ROBERT M. WALKER, Primary Examiner. 

1. A HERMETICALLY SEALED MOTOR-COMPRESSOR COMPRISING A COMPRESSOR, SAID COMPRESSOR INCLUDING A CYLINDER AND HAVING AN INTAKE MUFFLER CHAMBER AND EXHAUST MUFFLER CHAMBER HORIZONTALLY DISPOSED ON OPPOSITE SIDES OF THE CYLINDER, A MOTOR DRIVING THE COMPRESSOR, A FRAME HAVING THE MOTOR MOUNTED ON THE UPPER SIDE THEREOF AND THE COMPRESSOR MOUNTED ON THE LOWER SIDE THEREOF, A HERMETICALLY SEALED CASING ENCLOSING THE MOTOR, COMPRESSOR AND FRAME, SAID CASING HAVING RAISED SEATS IN THE BOTTOM THEREOF, AND THREE RESILIENT SUPPORT MEANS RESILIENTLY SUPPORTING THE FRAME AT THE UNDERSIDE THEREOF, SAID THREE RESILIENT SUPPORT MEANS BEING ARRANGED IN ANGULARLY SPACED RELATION AT SUBSTANTIALLY 120* INTERVALS ON A CIRCLE HAVING A DIAMETER SMALLER THAN THE OUTSIDE DIAMETER OF THE MOTOR AND BEING MOUNTED BETWEEN THE BOTTOM SURFACE OF SAID FRAME AND THE RAISED SEATS FORMED IN THE BOTTOM OF SAID CASING, AND SAID CYLINDER WITH SAID TWO MUFFLER CHAMBERS BEING DISPOSED BETWEEN TWO OF SAID THREE RESILIENT SUPPORT MEANS IN SUCH A MANNER THAT SAID TWO MUFFLER CHAMBERS ON THE OPPOSITE SIDES OF SAID CYLINDER ARE ARRANGED SUBSTANTIALLY ON THE PORTION OF SAID CIRCLE BETWEEN SAID TWO RESILIENT SUPPORT MEANS. 